Fixing Kotlin Lifecycle-Aware Components Issues

In Android development using Kotlin, Lifecycle-Aware Components such as LiveData, ViewModel, and LifecycleObserver help you write cleaner, more efficient code that responds to lifecycle changes. However, sometimes they may not behave as expected updates not firing, observers not triggering, or incorrect data states being rendered.

In this article, we’ll explore common causes of issues with lifecycle-aware components in Kotlin, and how to fix them using best practices and a full code example.

What Are Lifecycle-Aware Components?

Lifecycle-aware components are classes that can automatically adjust their behavior based on the current lifecycle state of an activity or fragment. These components help you manage things like UI updates, background work, and data streams efficiently.

Common lifecycle-aware components in Android include:

• ViewModel
• LiveData
• LifecycleObserver
• LifecycleOwner (implemented by Activity, Fragment)

Common Issues Developers Face

Here are the most common symptoms:

1. LiveData observers not being triggered.
2. ViewModel not surviving configuration changes.
3. LifecycleObservers not responding to events.
4. Data updating only after navigating away and back.
5. Multiple observers causing duplicate UI updates.

Let’s tackle these issues one by one with practical code.

Example Case: LiveData Not Updating UI Properly

Scenario

You have a simple counter app using ViewModel and LiveData. The problem: the counter value is updated in the ViewModel but not reflected in the UI.

Code Example (Broken Version)

// CounterViewModel.kt
class CounterViewModel : ViewModel() {
    val counter = MutableLiveData<Int>()

    fun increment() {
        counter.value = (counter.value ?: 0) + 1
    }
}

// MainActivity.kt
class MainActivity : AppCompatActivity() {

    private lateinit var viewModel: CounterViewModel

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        viewModel = CounterViewModel() // ❌ Wrong way: creates new instance

        val counterText = findViewById<TextView>(R.id.counterText)
        val button = findViewById<Button>(R.id.incrementButton)

        viewModel.counter.observe(this) { count ->
            counterText.text = count.toString()
        }

        button.setOnClickListener {
            viewModel.increment()
        }
    }
}

What’s Wrong?

The main issue is:

viewModel = CounterViewModel() // ❌ Direct instantiation

This bypasses the Android lifecycle and doesn’t preserve state.

Fixing It With ViewModelProvider

// MainActivity.kt
class MainActivity : AppCompatActivity() {

    private lateinit var viewModel: CounterViewModel

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        viewModel = ViewModelProvider(this).get(CounterViewModel::class.java)

        val counterText = findViewById<TextView>(R.id.counterText)
        val button = findViewById<Button>(R.id.incrementButton)

        viewModel.counter.observe(this) { count ->
            counterText.text = count.toString()
        }

        button.setOnClickListener {
            viewModel.increment()
        }
    }
}

Now, ViewModelProvider ensures the CounterViewModel survives configuration changes (like screen rotation) and behaves properly.

Additional Fix: Initialize LiveData with Default Value

class CounterViewModel : ViewModel() {
    val counter = MutableLiveData(0)

    fun increment() {
        counter.value = (counter.value ?: 0) + 1
    }
}

Issue #2: LiveData Observers Not Triggering

This happens when you use observeForever incorrectly or observe with a lifecycle that is not active. Always observe with the correct lifecycle owner (usually this for Activity or viewLifecycleOwner for Fragment).

Common Mistake in Fragment:

viewModel.counter.observe(requireActivity()) { ... } // ❌ Wrong

Correct:

viewModel.counter.observe(viewLifecycleOwner) { ... } // ✅ Correct

Issue #3: Multiple Observers on Same LiveData

Avoid adding observers in onCreate() without removing them. Otherwise, multiple observers may accumulate and cause UI glitches.

If using observeForever, ensure you call removeObserver() when no longer needed.

Issue #4: LifecycleObserver Not Reacting

Ensure you properly register the observer:

class MyObserver : LifecycleObserver {

    @OnLifecycleEvent(Lifecycle.Event.ON_RESUME)
    fun onResume() {
        Log.d("Observer", "Resumed")
    }
}

// In Activity:
lifecycle.addObserver(MyObserver())

Note: @OnLifecycleEvent is deprecated. Use DefaultLifecycleObserver instead.

Modern Approach:

class MyObserver : DefaultLifecycleObserver {
    override fun onResume(owner: LifecycleOwner) {
        Log.d("Observer", "Resumed")
    }
}

lifecycle.addObserver(MyObserver())

Tips for Stable Lifecycle-Aware Apps

Problem	Cause	Fix
LiveData not updating UI	ViewModel not scoped correctly	Use ViewModelProvider or Hilt/Dagger
Observer not triggered	Wrong lifecycle owner used	Use viewLifecycleOwner for Fragment
Duplicate UI updates	Multiple observers	Remove old observers or use SingleLiveEvent
Data lost on rotation	ViewModel created manually	Use ViewModelProvider or Hilt injection
Background task continues too long	Observer not removed	Observe and clear in onDestroyView() or onPause()

Final Thoughts

Lifecycle-aware components in Kotlin are powerful tools for building modern Android apps. However, incorrect use can cause them to behave unexpectedly. The keys to success:

• Use ViewModelProvider properly
• Always observe LiveData with correct lifecycle owner
• Don’t manually instantiate ViewModels
• Avoid multiple observers unless necessary
• Use DefaultLifecycleObserver for cleaner lifecycle handling

By understanding these principles, you’ll avoid common pitfalls and create apps that are more stable, maintainable, and user-friendly.